Internal-combustion-engine-temperature control



Jul 10, 1928. 1,677,103

P. S. TICE INTERNAL COMBUSTION ENGINE TEMPERATURE CONTROL Filed Jan. 1927 2 Sheets-Sheet l Illllljl July 10, 1928.

P. S. TICE INTERNAL COMBUSTION ENGINE TEMPERATURE CONTROL Filed Jan. 1927 2 Sheets-Sheet 2 Me! i Of'. PercjV'a Z 15'. I306 MM @1524 Zforge ya Patented July 10, 1928.

UNITED STATES PATENT OFFICE.

PERCIVAL S. TICE, OF CHICAGO, ILLINOIS.

:NTERNAL-coMBusTIoNmnemn-rismrnnarunn con-men ing different heat loss by radiation and different efficiency of the cooling apparatus for controlling the temperature of the cooling medium employed. It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings Figure 1 is a partly diagrammatic view of :the general character of a side elevation of an automobile engine including the customary radiator and cooling water circulatory connections, for indicating the relative positioning of the different parts involved in this invention with respect particularly to the engine and the radiator, the circulation means being of either the thermo-syphonic type,that is, efiected without any use of pump for producing forced circulation of the cooling medium,or by means-0f a pump in the water passage between the bottom of the radiator and the bottom of the cylinder jacket.

Figure 2 is a similar view in which the engine shownequippcd with this invention has a-pulnp for forced circulation of the cooling medium, and, in the circulatory system has the customary by-pass sometimes used for permitting more or less of the cooling water to by-pass the radiator to avoid the cooling action of the same with thermostatically and pressure-controlled valve in the lay-pass pipe.

Figure 3 is a detail section of the cooling water pipe connections from the. engine jacket to the radiator in an installation of the type indicated in Figure 1, showing on an enlarged scale both the pressure and thermostatic devices applied to one valvein a circulatory system for accomplishing the purpose of this invention.

Figure 4 is a view similar to Figure 3 showing a combined pressure and thermostatically operated valve in the by-pass of a force circulatory system shown in Figure 2.

Figure 5 is anelevation of an engine having forced cooling circulation with by-pass and having pressure controlled valve in the Application filed January 5, 1927. Serial No. 159,065.

by-pass pipe and thermostatically controlled valve in the pipe leading from the engine jacket to the radiator. v

Figure 6 is a sectional view showing the thermostatically controlled valve in the construction illustrated in Figure 5.

. Figure 7 is a sectional view showing the construction of the pressure controlled valve in the formv illustrated in'Figure 5. Figure 8 is a longitudinal section of the pipe leading from the engine jacket to the radiator having separate valves successively positioned in it, one controlled thermostatically only and the other both pressure and thermostatically controlled; 7

Figure 9 is a partly sectional view on an enlarged scale of a desirable form of the thermostat controlling. element which 'is embodied in the'forms shown in Figures 5, 6 and 8.

Figure 10 is an elevation of the pressure controlled valve shown in Figure 5, looking in the direction of the arrow, 10-10, on

Figure 5.

Before proceeding to describe the construe-- 'tion in detail, the principles and considera. tions derived from experience with automobile engines under various considerations of service which have led to and enter into the present invention may be briefly set forth.

Tests show that the fuel economy .of an engine otherthan at full load is improved by operating the engine with jacket-water temperatures that are higher than those ordinarily used in ordinary automobile operation.

water at the jacket outlet toward the radiator approximately at a temperature of 150 to 160 F. This is acompromise temperature range, being somewhat higher than that which permits full power development, and somewhat lower than that which permits maximum fuel economy.

The jacket water temperature-operates in two ways to affect the fuel economy; first 'by controlling the friction losses in the en gine which are substantially inversely as the vicosity of the lubricant, which in turn is inversely as the temperature of the lubricant film, thus making fuel economy vary approximately directly with the tempera ture of the jacket water; second, by afiecting the vaporization of fuel. Since only In many modern cars it is attempted bymeans of thermostats to keep the jacket than u that part of the fuel that is "vaporized to the, engine increases as the operatlit) / nearly corresponds to the engine tempora ing temperature increases until the temperature is reached at which all the fuel is vaporized. In automobile engines experiment shows that a water jacket temperature of from 190 to 200 F. is required to accomplish this. The vaporization is so nearly complete with the jacket water within this temperature range that much leaner mixtures can be used than those which satisfactorily operate at say 150 F.; thus accounting for a further possible gain in fuel economy at less than full load.

At full load or maximum power it IS found thatthe best general average temperature for the jacket is at or somewhat below 140 F., say 135 to 140 F. Temperature within this range is the best balance between the friction and the volumetricefiiciency-controlling factors, therefore permitting the engine to develop the greatestpower of which it is capable Since the close approach to maximum possible fuel economy is a main consideration under the demands of load conditions less than the maximum, and since maximum possible powers should be available under full load demand, it appears that the most desirable control of jacket water temperature will be such as to maintain engine temperature (jacket water temperature) within a range of 190 to 200 M under load conditions, substantially less than the maximum, and to reduce the'temperature automatically to within the range from 135- to 140 F. when operating at full load.

This is accomplished 'in the apparatus shown in the drawings in which a valve in the water circulating passage is controlled as -to degree of opening and closing for governing the rate of circulation betweenthe water'jacket and the radiator in suitable relation to the changes in intake manifold pressure which varies directly as the load demands upon theengine. Such intake manifold pressure control valve, however, cannot operate alone for exact control but will only operate in general for controlling in the right.- direction; and for obtaining accurate control of'water'jacket tem rature this pressure control must be sup emented by thermostatic controL' It is equally obvious that the thermostatic control alone cannot yield the exact result as to temperature necessary for the purpose. Accordingly the present invention consists in the provision of (yo-operating devices for modifying the circulation,-(a)' thermostatically according to the temperature of "the cooling water at a point in its circula tory course at which its temperature most nermoa ture resulting from engine operation and atmospheric conditions; and (b) in accordance with the intake manifold pressure which corresponds to the load demands upon the engine;

Referring to the drawings: The engine in totality is indicated at. A, with the intake 14, and is so shown in Figures 2 and 4, be-

ing illustrated as a pivoted valve, 15, dimensioned so as to stand closed to the limit at an angle of degrees across the water passage in which it is placed, as shown in dotted line in Figure 4,'a stop pin, 16, being provided to stop it at its wide open position which is extendin longitudinally of the pipe atan axial p ane thereof, as-

shown in full line in Figure 4. It will be understood that the valve is not fitted to the pipe so closely as .to totally exclude circulation past itat'the limit of its so-called closed position, but, on the contrary, there is always'enough of the circulatory fluid being pumpedthrough the by-pass and passing the valve' to keep the thermostatic device at the temperature of the circulated fluid. Experience shows that aone-eighth inch diameter hole through the valve plate, or an equivalent clearance around the valve, permits ample circulation for this purpose. Mounted in the by-pass pipe on a fixed stud,

,17,is abi-metallicspring member," 18, having one end portioncoiled spirally and securred at the inner end of the coil to the stud, 17,. the remaining portion of the bi metallic bar extending tangentially from the outermost coil of the spiral in a general direction longitudinally of the pipe and connected by a short link, 19, to the valve, 15, at a short distance from the pivot of the latter. This bi-m'etallic bar, hereinafter referred to as the thermostatic device, has its spiral coiled with the metal having the higher coefficient of thermal expansion at the outer side of the coil, and the parts are mounted and connected at ordinary atmospheric temperature as seen in Figure 4 with the valve at wide ooen position and the thermostatic spring device under slight tension for holdingthe valve at wide-open position slightlv pressed against the stop pin. When thus assembled, it will be understood that the rise of temperature of the water circulating through the by-pass pipe raising the temperature of the thermostatic device, will first relax the tension by which said device operating as a spring, holds the valve at" the-parts, the valve will reach closed position at which it is shown in dotted line in Figure 4. In accordance with the experien"e above recited as to the temperature at which ,fuel economy. and maximum power development respectively are obtained, an expert in this art, designing this construction, will proportion the 'several elements described so that the valve will be at fully closed position when the temperature has reached 200 F., thereby 'forcing the maximum circulation 61"; the cooling water from the engine jacket through the'radiator instead of throughthe by-pass.

If the valve were controlled solely by. the

thermostatic device, this would give "the maximum efficiency of fuel economy under' what might ,be termed ordinary running conditions, as distinguishedfrom the condi tion of maximum load reqi'liring the maximum power development of which the engine is capable without regard to fuel economy; and since there is direct relation hetween the intake manifold pressure and the load requirement of theengine by the. employment'of this intake manifold pressure to modify the valve opening in the direction of llastening the movement relatively to the temperature of the circulating fluid, and thereby preventing the temperature from becoming too high for the best power development, the engine will be enabled to develop its maximum power underthe stimulus oi the maximum load.

side of the passage containing the valve a pressure chamber, one side of which con.- sists of a flexible diaphragm, 4-0, rendering the chamber expansible and reducible; and extending from the side of the diaphragm whi= I1 is toward the pipe and through the wall of the pipe, a stem, 31, guided in'a' sleeve bearing, 32, mounted for that purpose in the pipe-wall, said stem being thus distruction in the two types. of circulatorv' system shown in Figures 1 and 3,1 and 2 and This is accomplished by provldlng mounted on the out- 4, respectively, and the following description will'apply eq'uallyto Figures 3 and 4. The chamber, 30, at the side opposite the flexible diaphragm wall of said chamber has a central hollow boss, 34, to whose outer end there is connected a pipe, 33, which leads to the engine intake manifold for in- 'troduction of intake manifold pressure into the chamber, 30, to cause its expansion and contraction and tocause the flexible diaphragm, 40, to-actuate the stem, 31, and hold it in operative relation'to the valve foraffecting the position of said valve as'ab-ove described in respect to said valve. in'the bypass passage. In the hollow boss, 34, there is mounted for sliding axially with respect to the diaphragm chamber wall, a plunger 36, having an expanded'head, 37, seating on the diaphragm and curved to accommodate the latter at its expanded position; and a coil spring, 41, in the"plunger stem, 43, which is'hollow to accommodate said spring reacting between the plunger, and a stop collar, 44, screwed into the outer end of the hollow boss, 34, deeply enough to leave outwardly from it, enough threaded length of the boss for connecting the. pipe, 33, leading from the engine intake manifold by a. coupling nipple, 34. At the outer side of the dia- .phragm, that is, outwardly with respect-to tioned yieldingly between the two springs, 35

and 41; lVith atmospheric pressure, .or nearly atmospheric pressure, in the intake manifold, thesprin 41, pushes the'p'lunger, 43,.t-he diaphragm, 40, and the stem, 31, inwardly with respect to the water passage tendingto hold the valve, 15, at aninthrust closed, or partly-closed, position tending to increase the freedom of circulation of the coolingwater between the engine jacket and the radiator, resulting in lowered tempera ture of the coolingwater, regardlcss of the action or tensioning of the thermostatic device. V

Upon reduction of engine output, as by motion of the engine throttle in a closing direction, the pressure'in the engine intake reduces in proportion to the change in load on the engine, and the communicating pipe, 33, transmits this pressure change to the din? phragm, 40, causing a proportionate compression of the spring, 41, and proportionate.withdrawalof stem, 31, under influence of its spring, 35, thus permitting a like pro portionate movement of valve, 15, in the direction to cause use of water temperature. The parts of the pressure actuated valve controlling device are proportioned so that the valve is free of pressure control at minimum Inn - pass pipe sure operated device,

' vcnient to locate Ill ofi' valve, the plug, 68,

- leading from the overcome the resistance sure is at the'maximum load intake manifold pressures, and is then solely undercontrol of the-thermostatic member.

The valve, 15, being located in the pipe line engine jacket to the radiator as seen in Figure 1, instead of in the byas seen in Figure 2, the proportions andadjustments of the partsat normal position are substantially as shown in Figure 3, thethermostatic device being connected with the "valve for holding it normally at the closed limit to be opened bythe thermostatic device upon rise of temperaturefandadapted in the absence of the intake manifold presto bring the valve to wide-open position against the stop pin when the temperature'reaches 200 F.; and .the pressure-operated device is mounted with respect to the valve so that the stem, 31, is in touch with the valve at the opposite side of its pivot from the connection of the thcrmo-- static device, and operates upon increase of pressure in the intake manifold beyond a predetermined minimum at which the pres sure acting on the diaphragm is sufficient to ofthe. spring, 35, to move the valve toward open position, regardless of the action of the thermostatic device, and so as to brin the valve to wideopcn position when the intake manifold presdue to maximum demand upon the engine. It is not essential that the two controls, thermostatic and by intake manifold pressure, should be applied. to the same valve. A close approach to optimum control of water temperature can be obtained with two valves, one of which is controlled by the temperature of the circulatory cooling fluid, while the other is controlled by intake manifold pressure. Two such valves are best employed in a forced circulation system having a by-pass, and it is usually most conthe' pressure-controlled valve in the by-pass pipe and the thermostatically-controllcd valve in the pipeline from the engine jacket to the radiator. :Such construction and arrangement is seen in Figure 5, whereinthe valve, 60, located in the pipeline, 152, is held by the thermostatic coiled spring, 61, normally at closed position when the engine is not running, and both engine temperature and intake'manifoldpres-. sure are atmospheric, the thermostatic device, 61, being constructed as hereinafter described to bcgin to-openthe valve when the temperatureof the circulatory fluid approaches F.,-and set it at wide open position shown in dottedline when the tem-- perature approaches -200 F In this form of installation the intake-,manifold-pressurecontrolled valve located in the by-pass assage, may be a simple form of plug siutbeing hollow andhaving a bellows extension, 70,of this hollow cylindrical body, the margin of said flexible mum developed when Figures 1 and 2,

F l 7 extension being clamped 71, of the slideway, 63 of the plug, with a coil spring, 74, housed in. the cavity of the hollow plug member rea'cting'between said member and the plug, closing the valve, said cover having an aper' tu'red nipple, 73, for connecting the valve by the pipe, 76,-.with the engine intakemanb fold, tlie spring,'74, being of such stiiinessi and length as to cause closed with intake manifold pressure nnder engine conditions for'developin maximum power, and- .to be,fully open wien the intake manifold pressure declines the engine is idling.

" In the simple arrangements of parts of supplemented by Figures 3 and 5 respectively, keep the water temperature from going below the desirable minimum value, or. to bring it up quickly to the desirable minimum, as

in cold weather when the cooling or heat between the cover,

71, in thedirection for the valve to be held to the mininopr ovision is made to.

dissipating capacity of theradiator is rela:

tivelyhigh. In both cases, Figures 1 and 2, application of full load brings the full cool-' ing capacity of the razzdiator into play, regardl'ess of temperatur This is obviated in Figure 8' in which two valves are employed, valve, 15*,being only 'under thermostatic control so that it remains closed-until attainment of the mlnimum de-- sired water temperature, say degrees F. to degrees F., and valve 18, under combined pressure and thermostatic control as described above, the thermostat being set to open the valve in the range degrees to 200 degrees F. This arrangement sto s all circulation of water through the ra 'ator unti'lattainment of the minimum desired temperature, when valve, 15?, opens, bring: ing valve, 18, into control as describec above. The arrangement of Figure 8 is prob ably the commercially most desir'ablepart 0: this invention, since. it operates umversalh and equally well with all types and varia 'tions of circulatory systems-as thermo syphonic, or forced circulation with or with out. radiator by fans, etc. It also,'as notec maintains both upper and lower temperatur limits by direct thermostaticcontrol.

The specific form of thermostatic elemei shown in Figures 5,6, 8 and 9 consists of spirally coiled bi-mctallic strip, onecnd which is attached to a pintle, 80, which pr jects into the pipe at one side for plvotri the valve, -co-operating for that purpose wr a pintle, 81, projecting in from the OPPQS] side, the other end of the spiral being 2 tached to'the valve whiclris a metal stanl ing formed with a diametrically extendl: semi-cylindrical boss and recess, 82, nto-t opposite ends of which the two pmtles p1 ject and in which the spiral thermostat c e d. The pintle, 80, 1s

ment is positione through a bushing, 84, fixed 1n thepipe a exteriorly provided with a spring arm, 85, terminating as a pawl at 86 for en aging a ratchet toothed flange, 87, with which the bushing, 84:, is provided, the pintle being turned in the bushing to suitably coil .the spiral device as a spring to cause it to react for holding the valve at closed position when the parts are cold,that is, at atmospheric temperature, adapted to begin to open the valve upon the relaxing of the coil as the temperature approaches 130 F., as above described.

In referring to intake manifold pressure varying in accordance with the engine' speed and load demands upon the engine, it is not overlooked that said intake manifold pressure under all running conditions is subatmospheric, and the variation in this subatmospheric pressure or suction is made available for the purpose indicated by the spring, 41, acting normally for holding the diaphragm chamber. expanded against exterior atmospheric pressure which is the force operating mechanically forv the movements described.

It will be obvious that within the scope of the invention a great variety of mechanical devices may be substituted for the diaphragm chamber and connections for causing changes in intake manifold pressure to operate the valve and also that the thermostatic device may be constructed in a great variety of forms. and I do not limit myself to the specific devices shown in either of these respects.

I claim:

1. In combination with an internal combustion engine having a circulatory cooling system comprising a water jacket and a radiator in circulatory relation thereto, valve means for controlling the rate of circulation between the engine jacket and the radiator. means connected for being affected 1 and responsive to the engine intakemanifold pressure with operating connections from said pressure-responsivemeans to said valve means arr: nged for moving the valv to augment the water circulation through the radiator upon predetermined rise of iiitake manifold pressure, and to diminish the water circulation through the radiator upon reduction of said pressure.

2. In combination with an internal combustion engine having a circulatory cooling system comprising a water jacket and a radiator incirculatory relation thereto. valve means for controlling the rate of circulation between the engine jacket and the radiator: thermostatic means positioned for being affected by and responsive to the engine temperature, with operating connections from said thermostatic meanstogsaid valve means, and means connected :for being affected by and responsive to the intake manifold pressure, with operating connections from said pressure-responsive means to said valve meansarranged for increasing the opening, f"the" vaflve. upon predetermined rise of intake-manifoldpresstire, and diminishing said opening: .upon reduction "of said pressure.

3. In the construction; defined in claim'l, the pressure-responsivemeans consisting of a flexible diaphragm, a chamber of which it constitutes part of the enclosing wall; fluid pressure connections from the intake manifold to said chamber andoperating connections from said diaphragm to said valve means. 1

4. In the construction definedkin claim 1, the pressure-responsive means consisting of a flexible diaphragm, a chamber of which it constitutes part of the enclosing wall; fluid pressure connections from the intake inanifold .to said chamber; yielding means resisting the chamber-enlarging movement of the diaphragm, and operative connections from said diaphragm to the valve means 5. In the construction defined in claim 1, the pressure-responsive means consisting of a flexible diaphragm, a chamber of which it constitutes part of the enclosing wall; fluid pressure connections from the intake inanifold to said chamber; means opposing the chamber-enlarging movement of the diaphragm, adapted to yield to permit such movement upon the access of predetermii'ied pressure from the intake manifold, and adapted to yield gradually for operating the valve means proportionately to the increase of said intake manifold pressure to a predetermined limit.

6. In the construction defined in claim 1, the pressure-responsive means comprising an expansible and reducible chamber having a fiuid pressure connection with the engine intake manifold; a movable member of said chamber by whose movement the chambee is expansible and reducible, operatively connected with the valve means, and yielding means opposing the chamber-expanding movement of said movable member constructed for opposing unyieldingly a prede- 

